Solder paste print qualification using laser triangulation

A method for determining the printability of a solder paste has been developed using laser triangulation based sensor hardware. The noncontact attribute of this measurement method is ideal for wet print measurements. The effect on material printability of both formulation and process elements are discussed. Results indicate that powder size has a definite and significant effect on the printability of the solder paste for 20 mil pitch applications. Bare board outer layer anomalies are characterized by surface scans and virtual cross sections.